(function (d, c) {
    var e = d.documentElement,
      b = "orientationchange" in window ? "orientationchange" : "resize",
      a = function () {
        var f = e.clientWidth;
        if (!f) {
          return;
        }
        if (
          !/Android|webOS|iPhone|iPod|BlackBerry|SymbianOS|Windows Phone/i.test(
            navigator.userAgent
          )
        ) {
          // PC端不设置
          e.style.fontSize = "100px";
          return;
        }
        // 根据屏幕宽度动态设置font-size iphone pro max 14的屏幕宽度，可以根据设计稿定义
        e.style.fontSize = 100 * (f / 430) + "px";
      };
    if (!d.addEventListener) {
      return;
    }
    c.addEventListener(b, a, false);
    d.addEventListener("DOMContentLoaded", a, false);
  })(document, window);
 
  /*
   1rem=100px 
    */